Question

我要做的是获取一个包含2个字段的IEnumerable个对象，并查找其中一个字段中只有一个与第一个字段中的一个相关联。

换句话说，设置就像

using System;
using System.Linq;
using System.Collections.Generic;

public class Baz
{
    public string Foo { get; set; }
    public int Bar { get; set; }    
}

public class Program
{
    public void Main()
    {
        List<Baz> bazzers = new List<Baz>() {

            new Baz { Foo = "A", Bar = 1 },
            new Baz { Foo = "A", Bar = 3 },
            new Baz { Foo = "B", Bar = 1 },
            new Baz { Foo = "B", Bar = 1 },
            new Baz { Foo = "C", Bar = 2 },
            new Baz { Foo = "C", Bar = 2 },
            new Baz { Foo = "D", Bar = 1 },
            new Baz { Foo = "D", Bar = 1 }

        };

        // WANTED: An IEnumerable<Baz> that is like

       // { Bar = 1, LoyalFoos = 2 }, (because both "B" and "D" are paired only with 1)
       // { Bar = 2, LoyalFoos = 1 }, (because "C" is paired only with 2)
       // { Bar = 3, LoyalFoos = 0 }  (because there is no Foo that is paired only with the Bar 3)


    }

}

使用LINQ有一个很好的方法吗？

Answer 1

我不确定你想要什么输出。如果你正在为每个酒吧寻找忠诚的foos数量，也许是这样的事情：

<script src='<?php echo $config['dir_plugins']; ?>qroll.js'></script>
<script src='<?php echo $config['dir_plugins']; ?>validate.js'></script>
<script src='<?php echo $config['dir_plugins']; ?>hellios.js'></script>

或者如果你想要给每个忠诚的foo分组吧：

    var result = bazzers
        .Select(bazzer => bazzer.Bar)
        .Distinct()
        .Select(bar => new
        {
            Bar = bar,
            LoyalFoos = bazzers
                .GroupBy(bazzer => bazzer.Foo)
                .Count(group => group.All(bazzer => bazzer.Bar == bar))
        });

如何使用LINQ查询执行此操作？

1 个答案: